1. Technical Field
The present invention relates to surgical instruments and, in various embodiments, to minimally invasive surgical instruments having an articulating end effector.
2. Background
Endoscopic and other minimally invasive surgical instruments typically include an end effector positioned at the distal end of an elongate shaft and a handle at the proximal end of the elongate shaft allowing a clinician to manipulate the end effector. In use, the end effector is provided to a surgical site through a cannula of a trocar. At the surgical site, the end effector engages tissue in any number of ways to achieve a diagnostic or therapeutic effect. Endoscopic surgical instruments are often preferred over traditional open surgical instruments because they require smaller incisions that generally heal with less post-operative recovery time than traditional open surgery incisions. Because of this and other benefits of endoscopic surgery, significant development has gone into a range of endoscopic surgical instruments having end effectors that engage tissue to accomplish a number of surgical tasks. For example, end effectors have been developed to act as endocutters, graspers, cutters, staplers, clip appliers, access devices, drug/gene therapy delivery devices, ultrasound, RF, or laser energy devices, and other surgical instruments.
In use, the positioning of the end effector at the surgical site may be constrained by the trocar cannula. Generally, the elongate shaft of the device enables the clinician to insert the end effector to a desired depth and rotate the end effector about the longitudinal axis of the shaft. This allows the end effector to be positioned at the surgical site, to a degree. With judicious placement of the trocar and use of graspers, for instance, through another trocar, this amount of positioning is often sufficient. Depending upon the nature of the operation, however, it may be desirable to adjust the positioning of the end effector of an endoscopic surgical instrument. In particular, it is often desirable to orient the end effector at any one of multiple angles relative to the longitudinal axis of the elongate shaft of the instrument.
Movement of the end effector through multiple angles relative to the instrument shaft is conventionally referred to as “articulation.” Articulation is typically accomplished by a pivot (or articulation) joint being placed in the elongate shaft just proximal to the end effector. This allows the clinician to articulate the end effector remotely to either side for better surgical placement of the tissue fasteners and easier tissue manipulation and orientation. An articulating end effector permits the clinician to more easily engage tissue in some instances, such as behind an organ. In addition, articulated positioning advantageously allows an endoscope to be positioned behind the end effector without being blocked by the elongate shaft.
Approaches to articulating end effectors tend to be complicated because mechanisms for controlling the articulation must be integrated with mechanisms for operating the end effector. For example, for end effectors that have open and closable jaw features, the closure sleeve, drive member and mechanisms for articulation must be implemented within the small diameter constraints of the instrument's shaft. One common prior design involves an accordion-like articulation mechanism (“flex-neck”) that is articulated by selectively drawing back one of two connecting rods through the implement shaft wherein each rod is offset respectively on opposite sides of the shaft centerline. The connecting rods ratchet through a series of discrete positions.
Over the years, other forms of articulating end effector arrangements have been developed. For example, U.S. Pat. No. 7,670,334, entitled “Surgical Instrument Having an Articulating End Effector”, and U.S. Pat. No. 7,819,298, entitled “Surgical Stapling Apparatus With Control Features Operable With One Hand”, the disclosures of which are each herein incorporated by reference in their respective entireties, disclose various surgical instruments that employ articulating end effector arrangements that effectively address many of the shortcomings of prior instruments with articulating effectors.
Many prior surgical instrument arrangements also employ a component commonly referred to as a “nozzle” that is rotatably supported on the instrument handle and is attached to the elongated shaft. When the clinician desires to rotate the end effector about the shaft axis, he or she simply rotates the nozzle relative to the handle. When the clinician also desires to articulate the end effector, the clinician must actuate a slide bar or other form of articulation control member to accomplish the desired articulation. Such control devices (e.g., the nozzle and articulation bar/control arrangement) typically must be actuated by using both hands.
In performing many surgical procedures, it is desirable to effect a desired amount of end effector articulation and rotation by using only one hand. For example, many vascular operations require precise control of the end effector. In such applications, it would be desirable to be able to have a surgical instrument that employs a single control mechanism for selectively articulating and rotating the end effector that can be easily actuated by using the same hand that is supporting the handle portion of the instrument.
The foregoing discussion is intended only to illustrate some of the shortcomings present in the field of the invention at the time, and should not be taken as a disavowal of claim scope.